types of microscopes

types of microscopes

light

electron

probe

light

• Light - most widely 

  • Visible light and blue wavelength 

  • 1-200x mag, 10-200nm resolution

  • Whole cells and organelles

electron

• Electron - expensive, prep, training 

  • Electrons with specimen in a vacuum 

  • 1000-100kx mag, 1-0.1nm resolution

  • Prokaryotic cells, viruses, macromolecules, large atoms

probe

• Probe - least used, costly, prep, training 

  • Electronic probes that move over specimen service 

  • >100 mill mag, .01-10 nm resolution 

  • 3d surface of macromolecules and atoms 

light microscopes

• Bright field, confocal, phase contrast, dark field, fluorescence 

brightfieqld uses, features, image

• Uses 

  • count organism or cells 

  • View stained specimen 

  • View live unstained specimen 

• Features

  • Staining required usually 

• Image Created 

  • Bright Background with clear or colored specimen 

dark field uses, features, images

• Uses

  • Viewing living, unstained

• Features

  • Filter inhibits light from going through organism and instead reflected by organism 

• Types of images 

  • Dark background with bright specimen 

• Does not visualize intracellular structure 

phase contrast, uses, features, types of images

• Affects contrast, Uses specialized condensers and objectives that amplify differences between sample and background 

• Uses

  • View internal structures of live specimen 

  • Observe motility (cilia and flagella)

• Features

  • No staining necessary, so can view live specimen 

• Types of Images 

  • Shows light and dark area of microbes 

fluorescence

• Fluorophores or fluorescent molecules, give colors can detect. 

• Uses

  • Localize specific structures or molecules

  • Diagnostic Tool 

• Features 

  • Uses uv light to excite fluorophores

  • Visualize whole cells, structures or proteins and watch movements or interactions 

• Images 

  • Dark background with fluorescent structures. 

• Immunofluorescence 

  • Fluorescent dyes are linked to antibodies which find a cellular target and bind to it bringing the due that can visualize and locate the structure

confocal, uses, features, images

• Uses

  • Highly detailed structures 

  • 3d renderings 

  • Biofilms 

• Features

  • Uses a laser to focus plane by plane through the specimen 

• Images 

  • Single plane of structures stained with fluorescent die

electron microscope

• electron beams give shorter wavelengths and increase mag and res, no live specimen

scanning electron

• Uses

  • Visualize surface details

• Features 

  • 3d view of surface of cell or cellular structure bc electron beam reflects off specimen treated with gold or palladium

• Types of images

  • 3d rendering of surface or shell of the object

  • Whole specimen can be viewed

transmission electron

• Uses

  • Visualize internal ultra structural details of cells, viruses and bacteria

• Features

  • 2d view of subcellular organelles, substructures, or viral particles as electron beam passes through specimen

• Types of images

  • 2d highly magnified picture 

  • Can see density through darkness